It is anticipated that the next generation of mobile broadband communication systems (5G) will need to deliver 100˜1000 times more capacity than current 4G systems (e.g., LTE and WiMAX) to meet the expected growth in mobile traffic. Existing approaches to increase spectral efficiency are unlikely to meet this explosive demand in wireless data. Current 4G systems use a variety of advanced techniques including Orthogonal Frequency Division Multiplexing (OFDM), Multiple Input Multiple Output (MIMO), multi-user diversity, spatial division multiple access (SDMA), higher order modulation and advanced coding, and link adaptation to virtually eliminate the difference between theoretical limits and practical achievements. Accordingly, newer techniques like carrier aggregation, higher order MIMO, Coordinated Multi-Point (CoMP) transmission, and relays are expected to provide only modest improvement in spectral efficiency. One strategy for increasing system capacity that has worked well in the past is the use of smaller cells. However, the capital and operating costs required to acquire, install, and maintain a large number of cells can be challenging since a 1000 fold increase in capacity would, in theory, entail a 1000 fold increase in the number of cells deployed. Moreover as the cell size shrinks, there is a need to perform frequent handovers that increase network signaling overhead and latency.